Low-pressure drip system in reduced tillage cotton

Abstract

Research has shown the soil and water conservation advantages of subsurface drip irrigation. Low-pressure drip system (LPS) technology has shown a high potential for economically improving application efficiency of irrigation systems under sandy soil conditions in areas where water is scarce and/or expensive. Energy costs are reduced as less than 70 grams per square cm is needed for system operation. The low-pressure system is installed just below the soil surface, it operates at very low flow and pressure, and it can stay on for longer periods of time without generating runoff or deep percolation. This study is designed to assess LPS under a reduced tillage system without the use of any other irrigation method for stand establishment. This combines the benefits of increased water use efficiency and lower energy costs for improved irrigation efficiency and fewer tillage operations resulting in lower production costs and less airborne dust. Since the drip tape was installed two years ago, only 3 cultivation passes have been made. No major tillage operations, the kind that generate lots of dust, have been performed. LPS water usage was 15% less than furrow irrigation and yields of cotton (Gossypium hirsutum) and blackeye beans (Vigna unguiculata) were comparable to yields from furrow irrigation. This system does present some challenges in stand establishment on very sandy soils and with weed control, which continue to be investigated. Herbicides requiring incorporation were not used. Weeds can be controlled in cotton using glyphosate and other herbicides. Fewer chemical weed control options are available for blackeye beans. The LPS technology has many potential technical, energy and economic advantages over standard drip and subsurface drip irrigation.